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Some rockets use hydrogen and their pressure vessels aren't so heavy as to keep them stuck on the ground. You only need to contain the hydrogen for hours, not w
by ggreer 7y ago
Some rockets use hydrogen and their pressure vessels aren't so heavy as to keep them stuck on the ground. You only need to contain the hydrogen for hours, not weeks.
- hfkajshfaks 7y agoFew though, and only the largest ones and they have incredibly complicated and long (and dangerous - imagine having to deal with refueling a cyrogenic liquid after every leg) fueling. Most rockets use hydrocarbons for this very reason.